1. Technical Field
The present invention relates to a chip inductor, and more particularly, to a pattern electrode in a chip inductor.
2. Description of the Related Art
In accordance with recent remarkable development of electronic and communication devices, the electronic and communication devices are frequently used. Due to the frequent use, communication problems caused by interference between the devices also frequently occur. Therefore, regulations on electromagnetic interference have been tightened to improve electromagnetic environment caused by use of wireless communication devices and multimedia devices.
Accordingly, it is recently required to develop components for eliminating electromagnetic wave interference. Along with rapid increase in demand for the components, the components have been developed to have complicated functions, to be highly integrated and to be highly effective. Among others, laminated chip inductors are filters to eliminate high-frequency noise, and are commonly used in personal computers, telephones and communication devices.
A conventional chip inductor, as is disclosed in Korean Patent Laid-Open Publication No. 2001-0005161, mainly includes a laminate in which a number of magnetic sheets having printed inner electrodes are laminated, and external electrode terminals at two side portions of the laminate.
Here, the inner electrodes have the same shape for the sake of manufacturing convenience. For example, FIG. 11 shows the chip inductor proposed in the prior art document in which all of the inner electrodes 1 in the layers have electrodes patterned in the ∩ shape, except for the uppermost and lowermost layers.
In this structure, however, if a laminate alignment error between magnetic sheets occurs during the process of laminating hundreds of magnetic sheets, the inner cross-sectional area of the coil is greatly changed, such that inductance is not controlled to a constant value.
For example, if a magnetic sheet in the upper or lower layer is moved inward as shown in FIG. 12A, the length L1 between inner electrodes in the upper and lower layers is abnormally reduced, thereby reducing the inner cross-sectional of the coil. Further, if a magnetic sheet in the upper or lower layer is moved outward as shown in FIG. 12B, the length L2 between inner electrodes in the upper and lower layers is abnormally increased, thereby increasing the inner cross-sectional area of the coil.
Since recent electronic and communication devices have complicated functions, are highly integrated and miniaturized, it is necessary to more precisely control inductance. However, the change in inductance due to the laminate alignment error damages reliability of products, and especially in the case shown in FIG. 12B the inner electrode terminal and the external electrode terminal may cause a short circuit.